This invention relates to trailer hitches for pivotally connecting trailers and the like trailing vehicles to towing vehicles.
Trailer hitches such as coupling devices between automobiles and trailers are well known. Conventional trailer hitches comprise a ball and socket arrangement to provide a coupling between the towing vehicle and the trailer, the coupling essentially permitting relative horizontal movement of the towing vehicle and trailer during driving and parking. Although conventional ball and socket connections permit a large amount of relative angular movement in a horizontal plane, i.e. in turning and parking, between the towing vehicle and the trailer, only a limited amount of relative movement in a vertical plane and essentially no rotation or twisting of the trailer relative to the towing vehicle are permitted.
Load-leveling and load stabilizing trailer hitches are also well known in the prior art. These hitches utilize spring bars or leaf springs of various kinds mounted on or adjacent to a ball hitch. Load-leveling trailer hitches are used to form a bridge across the trailer coupling, thus tending to raise the rear of the towing vehicle and to transfer some of the trailer tongue load to the front of the towing vehicle and to the trailer wheels. Load-stabilizing trailer hitches are used to overcome the tendency of the trailer to sway or rock.
Because of the use of spring bars or other means of spring loading in load-leveling and load-stabilizing trailer hitches, the amount of relative angular movement in a vertical plane between the towing vehicle and the trailer is limited considerably. As a result, the overturning of a trailer often causes the towing vehicle to be overturned as well, resulting in serious damage to the towing vehicle or the trailer tongue or frame and personal injury to occupants or passersby.
The restricted movements allowed by the ball and socket hitch have caused trailers to become separated from the towing vehicles creating uncontrollable hazards.
The present invention permits the continued use of load-leveling and load-stabilization devices and combines with such devices the added features of permitting a trailer to completely rotate on a longitudinal axis through 360 degrees with relatively free pivotal movement in the vertical plane. The utilization of this invention substantially eliminates the separation of an overtuned trailer from a towing vehicle. A motorcyclist riding a motorcycle and pulling a conventional two-wheeled trailer coupled together by the hitch of the present invention is able to lean his or her bike into tight turns unrestricted by the inability of the trailer to bank.